The objective of this study is to comparatively appraise the environmental impacts of formulating two metal surface coating chemicals (Product A and B) that can substitute each other via life cycle assessment methodology. The effect of using various energy sources during manufacturing is investigated. The functional unit is defined as 1000 kg product. A cradle-to-gate approach is adopted as system boundaries. The explored environmental impact categories are as follows: global warming (GWP), abiotic depletion (ADP fossils and elements), acidification (AP), eutrophication (EP), freshwater aquatic ecotoxicity (FAETP), human toxicity (HTP), ozone depletion (ODP), photochemical ozone creation (POCP) and terrestrial ecotoxicity (TETP) potentials. GWP of Product A is 7 higher than that of Product B. For all the other impact categories apart from GWP, Product A yields lower results. FAETP, ADP elements, ODP, EP, HTP, POCP, AP, ADP fossil and TETP of Product B are 116, 72, 55, 49, 38, 33, 26, 26 and 18 higher than Product A, respectively. Noteworthy reductions on environmental impacts generated by energy consumption are obtained for almost all of the impact categories apart from ADP elements, when photovoltaic cells are used instead of grid electricity. Similarly, reductions in all environmental impact categories except for ADP elements are found in the case of using wind turbines instead of the grid. More than 95 decreases are observed for ADP fossil, AP, EP, GWP, ODP and POCP by getting energy from wind instead of grid. The most environmentally friendly energy alternative is addressed as wind energy except for ADP elements. It is recommended to perform LCA studies related to zinc phosphating chemicals, as very limited studies can be found. These results can be used to guide the environmental policies related to the chemical, metal and coating sectors. GRAPHICS .
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